When it comes to the kingdom of organisms, plants are extremely important parts of it. Plants are multicellular organisms that have an amazing ability to produce their own food from the carbon dioxide that’s in our atmosphere.
Plants also provide the foundation of a variety of food webs and animal life would not exist if there were no plants. The field of the study of plants is called botany and the scientists who study plants are called botanists. In this overview of plant biology, we will examine the process of photosynthesis as well as a variety of different types of plants and the different parts of the plants, such as the roots, leaves, and stems.
Plants utilize the energy from the sun to fix carbon dioxide so that they can produce sugars, which is called photosynthesis. These sugars that are produced through this process of photosynthesis provide the plants with the energy they need to not only survive but to grow and reproduce. As plants grow, they then become a great food source for animals, humans, and other organisms.
There are plenty of plants on earth with over 400,000 different species currently known and most of them produce flowers and fruit that they need to reproduce. Plans to produce flowers are part of a group called angiosperms.
Pine trees and other wood-based plants are part of gymnosperms, and they are non-flowering trees as well as lycophytes, mosses, and even ferns.
Plants began growing in water and then moved to the land about 500 million years ago. Living on land is very different from living and water, so plants have grown and changed over the years in order to survive in soil versus the ocean and other bodies of water.
Plants on the land began to separate out the way their body grows into roots, stems, and leaves. The roots absorb water and the nutrients that are found in the soil, while the stems are used to transfer those materials between the roots and the leaves where sugar is produced, which gives the plant the energy to survive.
The Process of Photosynthesis
When it comes to an overview of plant biology, we must talk about photosynthesis and it is a key topic. Photosynthesis is a process that occurs in the cells of plants by using the sun’s energy to produce sugars from water and carbon dioxide. This process is basically a series of different chemical reactions which happen to be some of the most important on the earth.
The green color that we see on the stems and leaves of plants is caused by chlorophyll, which is a molecule that can absorb light energy from the sun. The light energy that is absorbed can force chemical reactions with the carbon dioxide and water, which is what allows the plants to produce sugars as well as oxygen gas.
This particular chemical reaction can be written like this:
energy + water + carbon dioxide → sugar + oxygen
The process is really quite simple when it comes to photosynthesis because it simply takes the carbon dioxide from the atmosphere and converts it into sugar before releasing oxygen back into the atmosphere which humans and animals need to survive, as well as other organisms. Over time, the process of photosynthesis changes the atmosphere of the earth by increasing the amount of oxygen gas in the air.
Vascular Versus Non-Vascular
If you look at a plant’s leaves you can see veins running through them. This is part of a critical step in the way plant species have evolved over the years since they act like the vascular tissue of humans. In our bodies, vascular tissue transports our blood throughout our bodies in the leaf veins and plants have vascular tissue that transports water and nutrients throughout the bodies of the plants.
Before plants developed this vascular tissue, water was only able to enter the plant by diffusing through its cells, so that meant plants were unable to grow to be very big because diffusion does not provide enough energy and nutrition to support a larger plant. Once plants develop this vascular tissue, they are able to grow much larger than their previous versions, which is also how very large trees developed throughout the earth.
There are still some plant species that are non-vascular plants, but most contain vascular tissue. Examples of nonvascular plants would be liverworts and mosses and even some biologists consider green algae to be a form of a nonvascular plant. These plants are usually found in wet or moist environments since they rely on diffusion to be able to absorb water and grow.
There are still many species of non-vascular plants, but the vast majority of plant species contain vascular tissue. Non-vascular plants include organisms such as mosses and liverworts. Some biologists also consider the green algae to be non-vascular plants. Because non-vascular plants rely on diffusion to absorb water, they are typically found in moist environments.